An adapter is used with a leaching chamber or like article to change the invert elevation for a pipe which carries water to the article. The first end of the adapter fits a hole or other port on the article. The body of the adapter rotates about that first end, changing the elevation of the second end relative to the base. Stops on the adapter body limit rotation: in one direction so the first and second ends are vertically aligned; and in the opposing direction so that the lengthwise axes of the first and second ends lie in an inclined plane. Thus, three positive invert elevations can be set for an inlet pipe for a particular article: a first and second at each limit of rotation of the adapter, and a third and lowermost elevation, wherein the adapter is not used.